1. Field of the Invention
The present invention relates generally to a unit that includes an image conveyance member or an electrostatic transfer member. Further, the present invention relates to an image forming apparatus, which includes the unit, such as a copying machine, a facsimile machine, a printer, or a multifunction peripheral (MFP) including these functions.
2. Description of the Related Art
Conventionally, image forming apparatuses have been commercially produced in which a toner image formed on a photosensitive member is transferred onto a recording material via an intermediate transfer member. However, the intermediate transfer member can deteriorate if it is directly touched by a user. Therefore, it has been necessary to protect the intermediate transfer member from a touch by a user on the intermediate transfer member. Such a case can occur when the paper in the image forming apparatus jams, for example.
Accordingly, Japanese Patent Application Laid-Open No. 2004-318003 discusses an apparatus in which a protective cover is provided to protect an intermediate transfer belt. In the apparatus discussed in Japanese Patent Application Laid-Open No. 2004-318003, the intermediate transfer portion can retract so that the intermediate transfer member separates from the photosensitive member. The protective cover is fixed facing a surface on the side where the intermediate transfer member retracts from the photosensitive member. Accordingly, the intermediate transfer portion can be removed by the user when the intermediate transfer portion is retracted from the photosensitive member.
However, in the apparatus discussed in Japanese Patent Application Laid-Open No. 2004-318003, the protective cover is immovably fixed to the intermediate transfer portion. Therefore, there still is room for improving the space utilization efficiency of the image forming apparatus. In other words, the image forming apparatus can be made more compact. The apparatus discussed in Japanese Patent Application Laid-Open No. 2004-318003 is configured so that the intermediate transfer belt and the protective cover both retract from the photosensitive member by the same distance. Thus, the space required for this protective cover retraction also has to be secured.
Therefore, in the apparatus discussed in Japanese Patent Application Laid-Open No. 2004-318003, a recording material conveying mechanism located near the intermediate transfer portion must be arranged so that the protective cover does not contact the recording material conveying mechanism when the protective cover is retracted. Namely, the space required for protective cover retraction has to be sufficiently prepared beforehand.
Thus, in a configuration in which the protective cover is immovably fixed to the intermediate transfer portion, the space required for protective cover retraction is increased. Therefore, space utilization efficiency in the image forming apparatus is low.
This problem can also arise for a photosensitive unit which conveys the toner image to the transfer portion using a photosensitive member. That is, if the protective cover for protecting the photosensitive member is immovably fixed, similarly, the space utilization efficiency in the image forming apparatus is decreased. Hereinafter, the intermediate transfer member and the photosensitive member may also be referred to as “image conveyance member”, and the intermediate transfer portion and the photosensitive unit may also be referred to as “image conveyance unit”.